Acta Botanica Croatica, Vol. 42 No. 1, 1983.
Short communication, Note
A study of Taxonomical Relations Between the Species Centaurea rupestris L. i C. fritschii Hayek, and their Spontaneous Hybrid C. x sordida Willd. (Asteraceae, sect. Acrocentron Cass. 1926)
Zinka Pavletić
; Hrvatska
Ivo Trinajstić
; Hrvatska
Abstract
Owing to special ecological conditions, which are primarily the result of general climate, the coastal slopes of the Dinarids make the border between two large floral areas, namely the Mediterranean and the North- -American — Euro-Sibirian regions. In both regions there are several genera represented by related species, some of which are limited to the Mediterranean region only and others to the North-American — Euro- Sibirian region. Very often, however, under certain ecological conditions, the areas of those species either touch upon each other or overlap, so that where there are no genetic barriers, hybridisation occurs and their hybrids and hybrid-swarms appear.
In studies of the genesis of endemic Illyrian and Illyrian — Balkanic species, investigations of the hybrids, which have already been found in the coastal belt of the Dinarids, are of a great importance.
The present paper examines the species C. rupestris and C. fritschii and their spontaneous hybrid C. X sórdida. A comparative morphological analysis has been made of ripe fruits coming from the populations of Croatia (Yugoslavia). The fruits were collected both in the localities where are areas of the species C. fritschii and C. rupestris overlap, and in places where only C. fritschii or C. rupestris grows.
The lenght of achenium and pappus and their interrelation proved to be significant; the results are shown in Table 1.
The variability and distribution of some parameters within the populations where the hybrid C. X sórdida occurs (where the areas of the two species overlap) and comparisons with the same parameters of C. rupestris and C. fritschii from the localities where only one of them grows, suggest that Fi generation is not sterile, as has been considered so far.
It is necessary to investigate the caryotypes of the general complex of C. rupestris, C. fritschii and C. X sordida, which should throw more light on the process of postglacial differentiation of neoendemics in this part of Europe.
Keywords
Hrčak ID:
158818
URI
Publication date:
31.12.1983.
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